Refactor Content-Range response header parsing into http_util

net/http/http_util.h

Index: net/http/http_util.h
diff --git a/net/http/http_util.h b/net/http/http_util.h
index 8658b57883782b9975ba418be71b38740a52c2c9..fe68423f6085473cd8af01f4bcbae363c063d308 100644
--- a/net/http/http_util.h
+++ b/net/http/http_util.h
@@ -6,6 +6,7 @@
 #define NET_HTTP_HTTP_UTIL_H_
 
 #include <stddef.h>
+#include <stdint.h>
 
 #include <string>
 #include <vector>
@@ -59,6 +60,21 @@ class NET_EXPORT HttpUtil {
   static bool ParseRangeHeader(const std::string& range_specifier,
                                std::vector<HttpByteRange>* ranges);
 
+  // Extracts the values in a Content-Range header and returns true if they are
+  // valid for a 206 response; otherwise returns false.
+  // The following values will be outputted:
+  // |*first_byte_position| = inclusive position of the first byte of the range
+  // |*last_byte_position| = inclusive position of the last byte of the range
+  // |*instance_length| = size in bytes of the object requested
+  // If any of the above values is unknown, its value will be -1.
+  // TODO(sclittle): Change this method to only support Content-Range headers
+  // from 206 responses, since right now it only has incomplete support for
+  // Content-Range headers from 416 responses. See crbug.com/670913.
+  static bool ParseContentRangeHeader(base::StringPiece content_range_spec,
+                                      int64_t* first_byte_position,
+                                      int64_t* last_byte_position,
+                                      int64_t* instance_length);
+
   // Parses a Retry-After header that is either an absolute date/time or a
   // number of seconds in the future. Interprets absolute times as relative to
   // |now|. If |retry_after_string| is successfully parsed and indicates a time